Research on Lead and other metals
in Sediments and Soils
Timothy Thorpe Allen, Ph.D., P.G.
Most of these projects were presented at the annual Keene State College Acadamic Excellence Conference, and many have been incorporated into published abstracts of presentations given at regional scientific meetings, or peer-reviewed journal articles.
Contamination of Soils on the KSC Campus from Lead Paint (2008)
Nasra Al-Hashmi, Emily Archer, Lauren Cram, Anthony Daniels, Joshua
Decknick, Jaclyn Oster, Aileen Shaw, Joshua Starkey, Melissa Sweeney,
Thomas Zimmerman, Michael Avery, Geoff Cornell, Keith Donovan, Jon
Paquette, Nicholas Raymond, Sena Tay, and Dene Tully
Recently the KSC Child Development Center playground was
found to be contaminated with chips of leaded paint. Lead exposure is
known to cause severe health effects in children. We were engaged to
determine how widespread this problem is across the rest of the campus.
We collected samples of paint chips and soils from around the perimeter
of selected buildings built prior to the banning of lead paint. Paint
chips were qualitatively scanned for the presence of lead using X-ray
fluorescence spectrometry (XRF). Soil samples were dried, pulverized and
pressed into powder pellets, which were then quantitatively analyzed for
total lead concentration by XRF. All of the paint chip samples scanned
had lead present. Soil lead concentrations range from 109 mg/kg to
22,486 mg/kg. Most of the buildings have soil lead levels well above the
US-EPA's recommended action levels of 400 mg/kg for play areas, and
1200 mg/kg for non-play areas.
See also Allen, 2008, under Published Abstracts and Papers,
below. This work was also reported on by the Keene Equinox Newspaper, Tests Reveal Lead Elsewhere on Campus
The Extent of Areas Containing High Concentrations
of Lead and Copper in the Ashuelot River Sediments (2005)
Lead and Copper are heavy metals which in high
concentrations are toxic to plants and animals. The Ashuelot River in
New Hampshire runs through many communities including the historically
industrialized city of Keene. A previous study, done by Allen and
others (2003), found that in certain sections of the river, sediments
contain levels of Copper and Lead higher than the "Upper Effects
Threshold" as defined by the National Oceanic and Atmospheric
Administration's Coastal Protection and Restoration Division (Buchman,
1999). This study builds upon this precursor by to confirming the high
levels of lead and copper in these areas as well as the extent of these
areas. The sediments are analyzed by X-ray Fluorescence Spectrometry in
order to construct a cross-section of the areas of concern.
See also Allen & Burns, 2006, under Published Abstracts and Papers, below.
Phytoremediation of Lead in Ashuelot Riverbank
Soil Using Brassica juncea (2004)
Past studies have found that the sediments in the Ashuelot
River at the Keene State College Railroad Trestle have high levels of
lead. This leads to the possibility that the banks of the Ashuelot River
may also have high levels of lead. Exposure to lead is dangerous to the
health of humans and to the environment, so an experiment was created
that attempted to reduce the levels of lead in the soil of the banks of
the Ashuelot River through phytoremediation. Phytoremediation is the
process of plants removing contaminants from the soil by absorbing the
contaminants into the plant itself. The plant Brassica juncea, "Indian
Mustard" grew in pots of soil collected from the banks of the Ashuelot
River. The collected plant and soil samples were analyzed for lead
content by x-ray fluorescence spectrometry.
Certain plants, such as Indian Mustard (Brassica juncea), are known
to hyper-accumulate some metals, thus reducing the amount of these
metals in the soil. In phyto-remediation, these plants are used to clean
up contaminated soils. After the plants have absorbed the contaminant,
the plants are dug up, dried, and properly disposed of in landfi lls.
Thousands of cubic yards of contaminated soil can be reduced to just a
few yards of dried plant material.
Environmental Studies student Sarah Ritter grew Indian Mustard plants
in some soil known to have a high Lead content as well as a control
soil, and over the course of the experiment analyzed both the plants and
the soils for lead content using the XRF spectrometer. She found that
plants grown in the lead-contaminated soil contained lead, while those
grown in lead-free soil did not. Sarah also found that, over time, the
total amount of lead contained in the plants grown in the
lead-contaminated soil did increase (the plants were accumulating lead),
although there was insufficient growth to significantly reduce the
amount of lead in the soil. Next time, we'll give the plants some
Heavy Metal Concentration in Ashuelot River Sediments (2003)
Michelle Comeau and Heather Carson
A reconnaisance assessement of heavy metal contamination of
sediments in the Ashuelot River, southwestern New Hamphire, using X-ray
fluorescence spectrometer, suggests that there is widespread Nickel and
Lead contamination all along the river. Significant concentrations of
Lead are found at some sites within the city of Keene. Chromium
contamination could not be determined quantitatively due to a problem in
sample preparaton, but is suggested--particularly in Keene--by the
results. Copper is generally low, except at one localized "hot spot,"
but becomes somewhat elevated downstream. Sediments enriched in Zinc
slightly above expected background concentrations are widespread, but
there are no extreme values.
See also Allen, et al., 2003, under Published Abstracts and Papers, below.
Published Abstracts and Papers
Allen , T., 2008, Contamination of Soils and Sediments in Keene, NH, from Lead Paint, Geological Society of America Abstracts with Programs, 40(2):8
Allen, T.T., and Burns*, E., 2006, Occurrence and Distribution of Trace-Metal-Contaminated Sediments in the Ashuelot River, Keene, N.H., Geological Society of America Abstracts with Programs, 38(2):12
Allen, T., M. Comeau*, H. Carson*, and E. Hurd*, 2003, A Reconnaissance of the Heavy Metal Content
of Ashuelot River Sediments, Studies in New England Geography, Number 17, 23 pages.